Re: Cassandra read process

Did you look at the answer the guy gave? -- Rahul Singh rahul.si...@anant.us Anant Corporation On Apr 17, 2018, 5:12 AM -0500, vishal1.sha...@ril.com, wrote: > Dear Community, > > Can you please help in answering the question below: > > https://stackoverflow.com/questions/497

Re: where does c* store the schema?

It uses a “everywhere” replication strategy and its recommended to do all alter / create / drop statements with consistency level all — meaning it wouldn’t make the change to the schema if the nodes are up. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Apr 17, 2018, 12:31 AM -0500

Re: copy from one table to another

1. Make a new table with the same schema. For each node 2. Shutdown node 3. Copy data from Source sstable dir to new sstable dir. This will do what you want. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Apr 16, 2018, 4:21 PM -0500, Kyrylo Lebediev <kyrylo_lebed...@epam.com>,

Re: Cassandra datastax cerrification

It’s good for a certification... there was a discussion in this list two weeks ago on the same subject. Summary: 1. Yes it’s fine. 2. You need experience or talent to get hired. 3. Talent can be either proven experience or your activity on the Cassandra project. -- Rahul Singh rahul.si

Re: Nodetool repair multiple dc

Makes sense it takes a long time since it has to reconcile against replicas in all DCs. I leverage commercial tools for production clusters, but I’m pretty sure Reaper is the best open source option. Otherwise you’ll waste a lot of time trying to figure it out own your own. No need to reinvent

Re: How to restrict users to specific DC.

That seems to be more of a network segmentation issue. Protect the other nodes behind a firewall / security group. Each node in the different DCs would be able to talk to each other but the user client machine can only access the traffic only DC -- Rahul Singh rahul.si...@anant.us Anant

Re: Urgent Problem - Disk full

Nothing a full repair won’t be able to fix. On Apr 4, 2018, 7:32 AM -0400, Jürgen Albersdorfer , wrote: > Hi, > > I have an urgent Problem. - I will run out of disk space in near future. > Largest Table is a Time-Series Table with

Re: datastax cassandra minimum hardware recommendation

Agree with Alain. Remember that DSE is not Cassandra. It includes Cassandra, SolR, Spark, and Graph. So if you run all of some , it’s more than just Cassandra. OpsCenter is another thing altogether. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Apr 4, 2018, 5:42 AM -0400, Alain

Re: Is Cassandra used in Medical industry?

Is that an encryption related policy? If you can clarify — maybe able to get better answers. There are products like Vormetrics (?) which can encrypt data at rest. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Mar 29, 2018, 12:23 AM -0400, Sudhakar Ganesan <sudhakar.g

RE: RE: 答复: A node down every day in a 6 nodes cluster

It may be that the wife partition is bombarded more than other partitions. What’s your RF on that keyspace? If if it’s greater than 1 I’d expect other nodes to get the same type of load. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Mar 27, 2018, 5:56 AM -0700, Kenneth Brotman

Re: Can "data_file_directories" make use of multiple disks?

Yes you can have multiple entries from multiple disks. No guarantee as I can see of even distribution. If you want even distribution there are better mechanisms for this at the filesystem later. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Mar 27, 2018, 8:05 AM -0700, Venkata Hari

Re: Cassandra certification

. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Mar 24, 2018, 5:38 AM -0700, Chandan Goel <cgo...@sapient.com>, wrote: > Hi, > > Is the professional certification on Cassandra given by Datastax recognized ? > Oreilly has stopped giving any certifications , it seems.

Re: Using Spark to delete from Transactional Cluster

really old data expire .. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Mar 23, 2018, 11:38 AM -0700, Charulata Sharma (charshar) <chars...@cisco.com>, wrote: > Hi Rahul, > Thanks for your answer. Why do you say that deleting from spark is > not elegant?? Th

Re: Using Spark to delete from Transactional Cluster

which will eventually get cleansed. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Mar 22, 2018, 2:19 PM -0500, Charulata Sharma (charshar) <chars...@cisco.com>, wrote: > Hi, >    Wanted to know the community’s experiences and feedback on using Apache > Spark to del

Re: How to Protect Tracing Requests From Client Side

Execute ‘nodetool settraceprobability 0’ on all nodes. It does zero percentage of he tracing. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Mar 22, 2018, 11:10 AM -0500, shalom sagges <shalomsag...@gmail.com>, wrote: > Hi All, > > Is there a way to protect C* on the s

Re: Is this SSTable restore merging scenario possible ?

If its not on the same “cluster” and you are not using something like OpsCenter, the snapshotted files will have a diferent schema UUID for each entity. If you rename the files to have the matching UUID in the file names, then you should be able to do what you are talking about. On Mar 21,

Re: Delete System_Traces Table

I think he just wants to delete the test table not the whole keyspace. Is that correct? -- Rahul Singh rahul.si...@anant.us Anant Corporation On Mar 19, 2018, 9:08 AM -0500, Chris Lohfink <clohf...@apple.com>, wrote: > No. > > Why do you want to? If you don't use tracing the

Re: Best way to Drop Tombstones/after GC Grace

and continue. It may be a very simple fix on their end to save from potential risks, extra ongoing work, and bad practices. This kind of “system debt” catches up. Better to nip it now. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Mar 14, 2018, 7:31 PM -0400, Madhu B <odba.ma...@gmail.

Re: Best way to Drop Tombstones/after GC Grace

Then don’t write nulls. That’s the root of the issue. Sometimes they surface from prepared statements. Othertimes they come because of default null values in objects. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Mar 13, 2018, 2:18 PM -0400, Madhu-Nosql <odba.ma...@gmail.

Re: Best way to Drop Tombstones/after GC Grace

Are you writing nulls or does the data cycle that way? -- Rahul Singh rahul.si...@anant.us Anant Corporation On Mar 13, 2018, 11:48 AM -0400, Madhu-Nosql <odba.ma...@gmail.com>, wrote: > Rahul, > > Nodetool scrub is good for rescue, what if its happening all the time? > > &

Re: Best way to Drop Tombstones/after GC Grace

Do you anticipate this happening all the time or are you just trying to rescue? Nodetool scrub can be useful too. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Mar 13, 2018, 11:29 AM -0400, Madhu-Nosql <odba.ma...@gmail.com>, wrote: > I got few ways to Drop Tombstones- Ch

Re: Row cache functionality - Some confusion

it. It may get more if its not the full partition cache, but theres no code that inserts into the CacheService except https://github.com/apache/cassandra/blob/0db88242c66d3a7193a9ad836f9a515b3ac7f9fa/src/java/org/apache/cassandra/db/SinglePartitionReadCommand.java#L528 -- Rahul Singh rahul.si

Re: Cassandra at Instagram with Dikang Gu interview by Jeff Carpenter

into the mainstream - eventually I see bridges between Cassandra and blockchain for organizations that need speed as well as fault tolerance for the “ledger”. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Mar 12, 2018, 7:59 PM -0400, Jeff Jirsa <jji...@gmail.com>,

Re: Anomaly detection

via other tools. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Mar 12, 2018, 10:02 PM -0400, Fernando Ipar <ipar.ferna...@gmail.com>, wrote: > Hello Salvatore, > > > On Mon, Mar 12, 2018 at 2:12 PM, D. Salvatore <dd.salvat...@gmail.com> > > wrote: >

Re: Cassandra vs MySQL

of it. It’s not going anywhere. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Mar 12, 2018, 3:58 PM -0400, Oliver Ruebenacker <cur...@gmail.com>, wrote: > > Hello, > >   We have a project currently using MySQL single-node with 5-6TB of data and > some perfo

Re: Anomaly detection

Anomaly detection of what? The data inside Cassandra or Casandra metrics? -- Rahul Singh rahul.si...@anant.us Anant Corporation On Mar 12, 2018, 12:44 PM -0400, D. Salvatore <dd.salvat...@gmail.com>, wrote: > Hello everyone, > Do you know if exist a Cassandra tool that perf

Re: Archive cassandra old data into Hadoop

the retrieval and analysis to be. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Mar 12, 2018, 8:30 AM -0400, Javier Pareja <pareja.jav...@gmail.com>, wrote: > Hi, > > I understand that a well designed cassandra system will allow to query ANY > data within it at a

Re: Row cache functionality - Some confusion

satisfies the query if and only if it’s the head of the partition, if not it fetches it and saves it - I dont interpret it differently from what I have seen in the documentation. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Mar 12, 2018, 7:13 AM -0400, Hannu Kröger <h

Re: Row cache functionality - Some confusion

What’s the goal? How big are your partitions , size in MB and in rows? -- Rahul Singh rahul.si...@anant.us Anant Corporation On Mar 12, 2018, 6:37 AM -0400, Hannu Kröger <hkro...@gmail.com>, wrote: > Anyone? > > > On 4 Mar 2018, at 20:45, Hannu Kröger <hkro...@gmail.com&

Re: Adding new DC?

How did you distribute your seed nodes across whole cluster? -- Rahul Singh rahul.si...@anant.us Anant Corporation On Mar 12, 2018, 5:12 AM -0400, Oleksandr Shulgin <oleksandr.shul...@zalando.de>, wrote: > > On Sun, Mar 11, 2018 at 10:31 PM, Kunal Gangakhedkar > > <kg

Re: Adding disk to operating C*

My 1.5T bound is for high throughput for read and write with hundreds of nodes — specifically with needs for quick bootstrap / repairs when adding / replacing nodes. Lower the density the faster it is to add nodes. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Mar 9, 2018, 11:30

Re: Cassandra storage: Some thoughts

Interesting. Can this be used in conjunction with bare metal? As in does it present containers in place if the “real” node until the node is up and running? -- Rahul Singh rahul.si...@anant.us Anant Corporation On Mar 9, 2018, 10:56 AM -0500, Vangelis Koukis <vkou...@arrikto.com>,

Re: Adding disk to operating C*

m/a/31690279 > From: Niclas Hedhman <nic...@apache.org> > Sent: Friday, March 9, 2018 9:09:53 AM > To: user@cassandra.apache.org; Rahul Singh > Subject: Re: Adding disk to operating C* > > I am curious about the side comment; "Depending on your usecase you may not > want

Re: Is there any limit in the number of partitions that a table can have

The range is 2*2^63 -- Rahul Singh rahul.si...@anant.us Anant Corporation On Mar 7, 2018, 6:06 AM -0500, Javier Pareja <pareja.jav...@gmail.com>, wrote: > Hello all, > > I have been trying to find an answer to the following but I have had no luck > so far: > Is there an

Re: Cassandra Daemon not coming up

Singh rahul.si...@anant.us Anant Corporation On Mar 5, 2018, 6:26 PM -0500, mahesh rajamani <rajamani.mah...@gmail.com>, wrote: > I did not add any user and disk space was fine. > > > > > On Tue, Feb 27, 2018, 11:33 Rahul Singh <rahul.xavier.si...@gmail.com> > >

Re: Adding disk to operating C*

of data dirs across nodes. It makes automation of operational processes a little harder. As an aside, Depending on your usecase you may not want to have a data density over 1.5 TB per node. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Mar 7, 2018, 1:26 AM -0500, Eunsu Kim

Re: One time major deletion/purge vs periodic deletion

, hourly, etc. depending on the volume but it would spread out the actual deletes. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Mar 7, 2018, 3:26 AM -0500, Ben Slater <ben.sla...@instaclustr.com>, wrote: > I would say you are better off spreading out the deletes so compact

RE: Cassandra Daemon not coming up

Were there any changes to the system such as permissions, etc. Did you add users / change auth scheme? On Feb 27, 2018, 10:27 AM -0600, ZAIDI, ASAD A , wrote: > Can you check if you’ve enough disk space available ? > ~Asad > > From: mahesh rajamani

Re: Cassandra Summit 2019 / Cassandra Summit 2018

momentum is the worst killer of community. We can rally around one date and see how we do. You can count on DC Cassandra committing to make our part of it happen. Best, -- Rahul Singh rahul.si...@anant.us Anant Corporation On Feb 27, 2018, 5:43 AM -0600, Carlos Rolo <r...@pythian.com>,

Re: Cassandra Summit 2019 / Cassandra Summit 2018

I think some of the Instaclustr folks had done one last year which I really wanted to go to.. Distributed / Async both would be easier to get people to write papers, make slides, do youtube videos with.. and then we could do a virtual web conf of the best submissions. On Feb 26, 2018, 1:04 PM

Re: Installing the common service to start cassandrea

Jeff, Check the service configuration to see what path it’s using for the JRE execution and if it’s specifying any class path parameters. The system user may not have the environment variables available whereas your user may have it. -- Rahul Singh rahul.si...@anant.us Anant Corporation

Re: Performance Of IN Queries On Wide Rows

That depends on the driver you use but separate queries asynchronously around the cluster would be faster. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Feb 20, 2018, 6:48 PM -0500, Eric Stevens <migh...@gmail.com>, wrote: > Someone can correct me if I'm wrong, but I belie

Re: Right sizing Cassandra data nodes

SSD drives. SSD doesn’t replace memory but it doesn’t hurt. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Feb 19, 2018, 5:55 PM -0500, Charulata Sharma (charshar) <chars...@cisco.com>, wrote: > Thanks for the response Rahul. I did not understand the “node density” point.

Re: newbie , to use cassandra when query is arbitrary?

lucene to help when doing arbitrary queries. Or you can use something else like MySQL / MariaDB for and then replicate the data through CQRS architecture to have a highly available database for read purposes only. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Feb 19, 2018, 9:44 PM

Re: newbie , to use cassandra when query is arbitrary?

SolR if your queries need to be on arbitrary columns across those hundred. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Feb 19, 2018, 11:31 AM -0500, Rajesh Kishore <rajesh10si...@gmail.com>, wrote: > It can be minimum of 20 m to 10 billions > > With each entry can c

Re: Right sizing Cassandra data nodes

the compactions etc. 3. Can have as much as you want for snapshots as long as you have it on another disk or even move it to a SAN / NAS. All you may care about us the most recent snapshot on the physical machine / disks on a live node. -- Rahul Singh rahul.si...@anant.us Anant Corporation

Re: newbie , to use cassandra when query is arbitrary?

How much data do you need to store and what is the frequency of reads and writes. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Feb 19, 2018, 3:44 AM -0500, Rajesh Kishore <rajesh10si...@gmail.com>, wrote: > Hi All, > > I am a newbie to Cassandra world, got som

Re: Cassandra cluster: could not reach linear scalability

If that is the case you could also try to run more stress from another machine as well. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Feb 18, 2018, 2:37 PM -0500, Jeff Jirsa <jji...@gmail.com>, wrote: > Stress client may be cpu bound as well > > -- > Jeff Jirsa >

Re: SSTableLoader Question

- which is with static files. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Feb 18, 2018, 9:22 AM -0500, shalom sagges <shalomsag...@gmail.com>, wrote: > Not really sure with which user I ran it (root or cassandra), although I > don't understand why a permission issue will gen

Re: Cassandra cluster: could not reach linear scalability

. Have you visualized the GC logs using something like VisualVM or hubspots GC visualizer? This is to see if there are chokepoints in the GC cycle. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Feb 18, 2018, 9:23 AM -0500, onmstester onmstester <onmstes...@zoho.com>,

Re: SSTableLoader Question

Check permissions maybe? Who owns the files vs. who is running sstableloader. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Feb 18, 2018, 4:26 AM -0500, shalom sagges <shalomsag...@gmail.com>, wrote: > Hi All, > > C* version 2.0.14. > > I was loading some da

Re: Cassandra cluster: could not reach linear scalability

You don’t don’t have enough memory. That’s just a start. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Feb 18, 2018, 6:29 AM -0500, onmstester onmstester <onmstes...@zoho.com>, wrote: > I've configured a simple cluster using two PC with identical spec: > cpu core i5

Re: Cassandra data model too many table

logical clusters? How much data do these queries return? If not a lot consider materializing the output into more general “cache” tables with set / collection columns when data is shoved when data is updated via triggers or spark. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Feb 18

Re: Refresh from Prod to Dev

if you don’t have an equivalent number of nodes. Otherwise if you can throw away Dev , just take everything from Prod and bring it up in a new Dev. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Feb 9, 2018, 1:18 AM -0500, Anshu Vajpayee <anshu.vajpa...@gmail.com>, wrote:

Re: Hints folder missing in Cassandra

Do you have any automation being applied via chef or likewise? Was the environment built using automation or using established images ? -- Rahul Singh rahul.si...@anant.us Anant Corporation On Feb 7, 2018, 10:37 AM -0600, test user <casst...@gmail.com>, wrote: > The directory

Re: Add column if it does not exist?

Yah. I saw one such migration via Spark Job running concurrently and created 4 Cfids and migrated data. It was a nightmare to cleanup the duplicated sstables. Alter schema and migrate should always be different applications separate from the actual system. -- Rahul Singh rahul.si...@anant.us

RE: Cassandra CDC

Ah got it. Good stuff. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Feb 6, 2018, 9:40 AM -0500, Nigel LEACH <nigel.le...@uk.bnpparibas.com>, wrote: > Not too much delving needed, I upgraded jamm to v0.3.2. I’m not entirely sure > why this was required, it seems a li

Re: Cassandra CDC

/cassandra-trigger/src/main/java/io/smartcat/cassandra/trigger/KafkaTrigger.java -- Rahul Singh rahul.si...@anant.us Anant Corporation On Feb 6, 2018, 5:50 AM -0500, Nigel LEACH <nigel.le...@uk.bnpparibas.com>, wrote: > Hello, I’m loading Cassandra (v3.10.0.1652) data into a Kafka (v1.0

Re: Increased latency after setting row_cache_size_in_mb

Could be the cause. I would run 2 and then 4 concurrent clients to see how they behave. What’s your client written in? How are you managing your connection? -- Rahul Singh rahul.si...@anant.us Anant Corporation On Feb 6, 2018, 8:50 AM -0500, mohsin k <moshinkarova...@gmail.com>,

Re: Add column if it does not exist?

Yeah, you can handle the exception — what i meant that it wouldnt cause harm to the DB -- Rahul Singh rahul.si...@anant.us Anant Corporation On Feb 5, 2018, 5:07 PM -0500, Oliver Ruebenacker <cur...@gmail.com>, wrote: > Well, it does throw an InvalidQueryException if the column alrea

Re: How to Parse raw CQL text?

? Did you look into this unit test folder? https://github.com/apache/cassandra/blob/trunk/test/unit/org/apache/cassandra/cql3/CQLTester.java -- Rahul Singh rahul.si...@anant.us Anant Corporation On Feb 5, 2018, 4:06 PM -0500, Kant Kodali <k...@peernova.com>, wrote: > Hi All, > > I ha

Re: Add column if it does not exist?

Since CQL != SQL, there’s isnt a syntatical way. Just run the alter table command and it shouldn't be an issue if its there. -- Rahul Singh rahul.si...@anant.us Anant Corporation On Feb 5, 2018, 4:15 PM -0500, Oliver Ruebenacker <cur...@gmail.com>, wrote: > > Hello,

Re: Increased latency after setting row_cache_size_in_mb

e partition size to be less than 1KB. > > > > > > > > > > > On Mon, Feb 5, 2018 at 5:37 PM, mohsin k > > > > > > <moshinkarova...@gmail.com> wrote: > > > > > > > Hey Nicolas, > > > > > > > > > &

Re: Increased latency after setting row_cache_size_in_mb

What is the average size of your partitions / rows. 1GB may not be enough. Rahul On Feb 5, 2018, 6:52 AM -0500, mohsin k , wrote: > Hi, > > I have been looking into different configurations for tuning my cassandra > servers. So, initially I loadtested server using

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